This invention relates to interception of traffic, in particular lawful interception of broadband traffic.
Lawful interception (e.g., wiretapping) is a common technique used by law enforcement agencies (“LEAs”) to intercept certain communications between parties of interest. Unlike illegal interception, lawful interception is performed in accordance with applicable (e.g., local, state and/or federal) laws. In particular, the communications that are intercepted under lawful interception may be subject to the limitations of due process and other legal considerations (e.g., Fourth Amendment). To further protect the parties of interest, intercepted communications may be authenticated to validate any claims in favor of or against the evidence (e.g., that the intercepted communication originated from a particular party, that the communication was intercepted at a particular time, etc.).
Lawful interception is usually accomplished with the help and cooperation of a service provider. The duty of the service provider to provide LEAs with access to otherwise private communications is governed by the Communications Assistance for Law Enforcement Act (“CALEA”). As first passed by Congress in 1994, CALEA was primarily concerned with voice communications, such as plain old telephone service (“POTS”) and, more recently, voice over Internet protocol (“VOIP”). However, with the growth of the Internet, LEAs have also sought to intercept data communications transmitted over broadband networks. To this end, CALEA was recently expanded to cover data communications in addition to the traditional voice communications.
Lawful interception of voice communications is generally well known. However, conventional techniques for intercepting voice communications may not be applicable to data communications due, at least in part, to the nature of data communications and its transmission over broadband networks. For example, while access to voice communications remains mostly static (e.g., the location of a landline phone, and in many cases, a VoIP phone, generally does not change), access to the Internet is often dynamic, as evidenced by the increasing availability of Wi-Fi hotspots at airports, coffee shops, and the like. Among other things, these publicly accessible hotspots increase the difficulty of intercepting broadband communications and associating the intercepted traffic to specific users.